Accurate O-H Bond Dissociation Energy Differences of Hydroxylamines Determined by EPR Spectroscopy: Computational Insight into Stereoelectronic Effects on BDEs and EPR Spectral Parameters

作者：Billone Paul S^*; Johnson Paul A; Lin Shuqiong; Scaiano J C; DiLabio Gino A; Ingold K U

来源：Journal of Organic Chemistry, 2011, 76(2): 631-636.

DOI：10.1021/jo1021794

Differences in O-H bond dissociation enthalpies (Delta BDEs) between the hydroxylamine of N-15-labeled TEMPONE and 10 N,N-di-tert-alkyl hydroxylamines were determined by EPR. These Delta BDEs, together with the g and a(N) values of the derived nitroxide radicals, are discussed in relation to various geometric, intramolecular dipole/dipole, and steric effects and in relation to the results from DFT calculations. We find that dipole/dipole interactions are the dominant factors in dictating aN values and O-H BDEs in all of these structurally similar nitroxides and hydroxylamines, respectively. The importance of including the Boltzmann distribution of conformations for each nitroxide in the aN calculations is emphasized.

• 出版日期2011-1-21